large cut lenses and a turn-over rim were certainly Stuart design features during the late 1930's, and the size of 10" agrees with some other similar material with this sort of rim - although I don't see one with Stratford Rings.** However, I think this stands a good chance of being from that factory. Might the wear be in line with that sort of date Keith? - and I assume by the way that this is lead glass and rings well?
I do have a piece of Stuart cut glass with the rings, so there's no doubt it wasn't only a feature of blown/moulded glass.
Other problem is that not all pieces were fully marked Stuart - some, for example have simply a discreet 'S' or -S-, as we've discussed before, and I know from experience that the 'S' can be elusive and difficult to locate.
**Ref. 'Art Deco to Post Modernism etc.' - Benson & Hayhurst - Exhibition Catalogue 2003.